Tool-guide



2 Sheets-Sheet 1 T V Z INVENTORS.

ATTORNEY.

ll'l II .I r

HEW-TH ORN BuRq L Sm \TH,

m U r Ill'l. I

March 4, 1958 H. w. THORNBUR\G ETAL TOOL-GUIDE Filed March 13, 1955 United States Patent 2,825,535 TOOL-GUIDE Herbert W. Thornburg and Irwin C. Smith, South Milwaukee, Wis., .assignors to Bucyrus-Erie Company, South Milwaukee, Wis., a corporation of Delaware ,ApplicationiMarch 13, 19.53, Serial'No. 342,149

7 Claims. (Cl. 255-5) This inventionrelatesto a new and useful tool-guide for cable-tool drills, more particularly to such a tool-guide which is removable from the line of drilling by automatic means when the drill-tool is retracted from the hole.

In a cable-tool drill a cable passes from a winchdrum on the main frame of the drill, around a heelsheave at or near'the front end of themachine, under a .spu'dding-sheave mounted on the free end of a spuddingbearnat or nearthe rear end of the machine, over a crownsheave near the upper end of the mast at the rear of the machine, and downward into the hole which is being drilled into the ground.

At the lower end .ofthis cable is a string of percussion drilling tools, terminating at a bit. The tools are reciprocating up and down by the reciprocating action of the spuddingsheave on the cable.

A tool-guide is normally constructed to be a cylindrical guide afiixed to the mast of the drill to be located vertically over the center line of the hole while drilling. This position of the tool-guide and tool is the normal drilling position. The tool-guide serves to keep the tools vertical and so make the hole verticaLespecially at the start of drilling. It also serves to prevent whipping of the cable. 7

When the tool is retracted from the hole for bailing, t e tool and tool-guide must be removablefrom the line of drilling to permit the bailer to belowered into the hole for bailing. This position of the tool and tool-guide, out of the line of drilling, is the bailing position.

In the past, tool-guides have consisted of one or two short-tubular pieces to be swung to one side when not in use, or a longer longitudinally-divided tubular piece 1 openinghorizontally to'permit extraction'of the tool from its guide. The swinging and tool extracting action has been accomplished by hand-operated tool-guide-retracting mechanism and the swinging of the toolout'of the line of drilling has usually been done manually'by swinging the drill-tool to one side of the hole, holding in that positiomand lowering the toolto rest on the deck-of the drill.

The short tubular guide encompasses only a smalljpart of the length and stroke of the tool, so that upon reciprocation the tool may momentarily leave'the guide and no longer be held to true vertical movement. That is, if such guides are mounted rather lowthere is, of course, no guide for the upper end of the tool at the start of a hole. If mounted rather high, the .tool willbe left unguided for considerable time as work progresses or until the major portion of the tool has entered the natural guide formed bythe well. Guides may be improved by using a plurality of short tubes. This, however, addsto the complication of the operator as considerable time and effort is required in clamping each tube in' position for drilling and loosening it in preparation for bailing. Also the addition of more of these parts adds to the effort required to move them sutriciently .to make wayfor'the bailer.

, 2,825,535 Patented Mar. 4, 1958' The longitudinally-divided tube is not a rigid guide, in that, after considerable reciprocating movement of the tool in the guide the tool slaps and bangs against the sides of the guide, thus tending to separate the two halves of the tubular guide. After the guide is thus loosened or spread, the .tool is not held to true vertical movement; also in this type of guide, when it is retracted from around the tool and the tool is raised from the hole, said .tool .muststill be swung to'one side to use the bailer. This swinging action .of-the tool :has heretofore always been accomplished manually.

In the prior art, tool-guides have required the operator of the drill to make the following adjustments in-retracting the drill for bailing: (1) He must unlatch the tool-guide, (2) He -must swingthe tool-guide out of the line of drilling, .(3) He must then swing the tools out of the line of -drilling manually, which in heavy drills requires considerable effort on the part of the operator, (4) He must fasten the ,tool a remote position, usually by holding the tool over the desired remote position and then lowering it to the frame v of the drill.

When the driller finishes bailing and desires to begin drilling again, the following movements are necessary beforedrilling can begin: 1) He must raise the tool ofi the frame of the drill and allow it to swing into position, (2) He ,must swing the tool-guide back into its normal drilling position located'vertically over the hole, and (3) He must latch the tool-guide. Y

A desirable feature for tool-guides, though not found in'the priorrart, is a means'whereby thetool-guide and tool may be automatically retracted from the line of drilling by actioniof the tool after raising it from the hole} This guide incorporatesv means for accomplishing this objective.

Accordingly the principal objects of this inventionare:

1) To provide a long and rigid tool-guide which, when itis retracted, does not interfere with bailingor replacement of tools. (2) To provide such a tool-guide that it will be retractable by power means which is r'eadily' available in the drill. (3) To provide a tool-guide to eliminate manual retraction of the tool frornfthe line of drilling. (4) To" provide a tool-guide that is-retractable by potential energy-of the tool whenraised out of the hole and thenlowerable. (:5) To provide a tool-guide which is also retractable by power raising of .the' tool. (6) To provide atool-guide which retracts vertically as well as horizon-tally. (7) To provide a constraining means to attach the'tool to the mast and allow the tool and the-guide to move-away from-the line of drilling. (8) To provide a constraining means such that, when the tool is moved horizontally sideways from the line of drilling, the tool and guide may be cocked-to give a cant effect, so that the force of the-rope exerted by the pull of the tool will pull from the center of the crown sheave, so as not to cause the rope tobecorne unthreaded from the sheave. (9) To provide a tool-guide which will absorb the shock from an upward blow by the tool against the lower end of the guide without harming its mounting on thedrill. 10) To provide a tool-guide; which when retracted will return to drilling position by potential energy available in the tool-guide and/or drill{ tools and be controllable through the rope and the; which of the drill. (11) To provide a tool-guide which is compact, simple, and easy to-retract. (12) To provide a tool-guide whichrequires a minimum of adjustment.

In addition to the principal objects, above statecha' number ofnovel and useful details have beeuworked out, which wi-llbe readily evident .as the description progresses.

This-inventionrconsists in-the novel parts and in .the combination and arrangementthereof, which are defined,

. in the appended claims," and'of which means for retracting the tool guideQ -to itsdetails; constitutes .no part of this'invention.

- nected to the upper species are r exemplified in the accompanying drawings, hereinafter,

particularly described and explained.

Throughout the description ;in;each of these variants the" same reference number isapplied to the samefirnember or tofsimilarmember's W lj j Figure l; is a-side" elevation of a cablegtooldrillshow ing the first variant of this invention; I if V I f: Figure -2 is an enlarged view of atool-guide similar 'to the OneshOWn-in Figure 'l,-elirninating the irope pulley means for retracting the tool-guide and showing in its place a second means for retracting the toolfguide. I

f Figure'4fis a sideelevation of a cable-tool drill" show ing a secohd constrainin'g means for the .tool-guidein this invention;

V 1 FigureS is an enlarged 'front view of Figure 4 taken a: i along lines 5+5, omitting the drill-tool, 'bit, and ,hook. Figure 5. adding the drill- V Figure 6 is'a side view of 'tool,'bit', and hook. f r V Referring .now to Figure 1, we see that 11 is theumain Figure 3 is a similarlyenlarg e dview of a toohguide as-shown' in Figure 2. 'This figure 'showsstill another to the left along with, it. When tool-guide'24fis restored 1 ,to its loweredposition, the hook 32 may beremoved from V f a d l-i091 4- -T e. p ratqtd s n es th w nch-clutch g toistophoisting;thejdrill-tool,'andthe'drill-tool'isflowered r V to resume drilling. I

frame ofthe drilling machine and 12 is the well:hole being drilled in the ground. 13 is anyco'nvenient'form of ground support forthe' drill, preferably, but not n e'ces w sarily, of'the endless -tread variety.

Drill-tool 141s suspended bya rope 15 t he raised orlowered through anopening 34 in the drill-frame and into the hole 12. Rope '15 passes. over a crown-sheave 18,'on'spudding-beam 19, thence around 'heel-sheave20 at the rear pivot'of beam 19,and thence to a winch-drum '21. I.The beam 19 is reciprocated by motor 2 2 acting through intermediate "unnumbered belting and gearing and crank ,23 lot ,pitman 24. .Various. methods, iwell. known in the art, can be; used to pay-out and take-in ropel5. r

' 16 at the .top of mast 17, thence around spudding-sheavenectionj-26. r v V V e f In this variant of theinvention, the power loweringof g -'the;drill-tool .14 is utilized to .swinglthe tool-guide. andy a minimum of operations .on-the'part of the operator."

jAfter bailing is completed ;.and it is desired to realign} 1' i the tool-guide 24'an'd drill-tool'lfiiwith the well-hole 1 2 .fordrilling, the operator. engages theclutchon thef drilL 1 v winch and raises the drill tool-r 14,- In solddihgQslackis] created in rope 29:andQthe.tool-guidelowersby-itsgown 2 weight into a normal'drilling positioninline-with the well- 'hole 12. As the tool-guide 2.4 lowers (counterclockwise) rotation about .pin' 27 in Figure :1 -)7 it carries' drill-tool 14 into-the well-hole :12-under f control of the :winch-braI ei 7 an length of ropezganambk s ziw ii1atemi iiefui Q height above the drill-frame'llj to which the drill-toolj14 'must he 'raised to engage hook 32 with drill-tool14. "The minimum? working height'to which the drill-tool 14 lig t-.

'raised tofengage hook 32 is limited to a distancebetween the lbit33 and the drill framefllequal to the length of raver arm: 2

measured between pin .27 and pin-con:

ammonium of the line of drilling and hold themin this removed position, whereas'in the priorgart it was necessary to move the tools and guide by'rhultiplemanualoperations V and with a greater consumption otv'time and energy on the 1 partl'of the operator. The .power raising ofithe drill-1..

The machinefthus 'far, described is conventional and; as

Let us now'turn to the tool-guide 24 and the'means for retracting theguide-24 from the line of drilling. This is the essence ofthisinvention and several variants are H fdescribedto achieve this result. r r In the variant of Figure l. the tool-guide 24 is a one piece tubular-guide mounted onthe mast'17 (Figure 1) Q l In describing this variantfofFigure' by lever arms 25. Lever arms 25 are U-shaped at one end so as to .fit 'aroundthe tool-guide 24'and bepin-cona nected by pins 26 to the sides thereof. The other end of said lever arms 25 extend horizontally from 'themastl7 and; are held from further rotation .downwardtcountei clockwise) by a stop 28; said:stop.28 as shownis an integral part of the mastl17, on the upper lever arm connection on the mast 17; but it is understood that. it is not necessarily limited to the upper lever am only: The

lever. arms 25 are free to rotate clockwise when the tool guide is moved from 'the drilling positiontsolid outline) a to the-bailing positionl (dotted outline) in Figure 1'. T 1 A rope 29 is attached to the upper end of theitool-guide 241at 'an eyelet 30 which is rigidly fastened to the tOOl-r' guide 24. The rope 29 extends over a sheave 31 suspended frorn mast 17 at'a point above the top oftoolguide 24 when it' is retracted to the bailingposition (shown indotted outline in Figure .1). From sheave:

' 3 1*the rope 29' extends downward to a-point where a hook 32is attached 'to the rooe 29 by tying it through an eyelet on the end of hook 32 vThe .hook end of part 32 istastenable to the bit 33 of drill-tool 14.2 Drill-tool 14 is threaded through tool-guide 24 and rope 15 is con'- end of drill-tool 14 by a conventional connecting means. V V e V As winch-drum 21 windson rope 15, the drill-tool 14 is lifted from well-hole 12 until' the drill-tool 14 isllifted into theatool guide 24to aposition where hook.32may be hooked onto drill-tool'14 at the bit 33. After the hookjn'engages thedrill-tool-lt, the operator lowers the '21. i'Asthe tool guide 24 swings upward and to the; right;

the drill-tool 14' is interlocked therewithand both of :these' 5 tool is utilized to swing the "tool-guide and dIil1rtQOl into line with the well-hole 12; thus' this inventionre:

fquires aminimum' of operations by the operator to ithe tool-guidefordrilling. 1 j V y 1 V Turningriow-to'Figurel, another variant of thisf. ven

tion is -descrihed for retractingthegtool-guide and drill;- tools fromthelineot drilling. r

tion; of the structurewhich changed from Figure? Figure 1, and is threaded through a one-piece 'tubiilar tool guide 524,- js'aid tool-guide being constructediso that it 'narrow'sfo a collarf36 'atits upper end. i Whenit is desired to swing the; tool-guide 24 and drill-tools 14 out of the line of drilling the'drill-tool 14 is hoisted b'y'the 1 powerlw'inch'of the drill 'to engage the top ofitheidrillg j tool 14 with theicollar 36fof "tool-guide" 24 ;-so meme 5 shoulder 36' Ton thettop of said tool will? bear against collar 36;" By"continuing to hoist the drill-tool l ig'jthi tool guide 24 will 'be' hoisted along Lwiththe drill toolf14 Tool-guide 24 is connected to the mast by lever arms-25 i "in the same manner as described'in Figure lihereof; so V thatfas thetool-guid tends to move upward vertically, it

also swings to. the right -clockwisein Figure 2) about pins parts 14 'and 24 arejre'moved fromtheline of -dr n of the'jdrill-winch" position".- T2

Whngthe' tool-guide"24:'and drill tool i14'are removed to. V

the retracted position (dotted outline in Figure 2) the I ope'ratorlcease's to' hois't thefdrill-tboharid sets the brake V thusj holding 'the tool in the' desired T 'When ba'iliiig ope the drill-wineh." rm; so doing; th drillvtoolrht. and tools} guide 24 swing' down -and to the left ('counterclockwisein Figure 2). unti1 the uppermost lever arm 25 engagesthe -j 2; i only thatjpor v rations are finished audit is desired to j realign the dril l-tool' 14 'withthe {well-hole 12for drilling; a theibpefatoflhrly lowers. the drill-tool14'byunspooling-5i 7 degrees).

'in'g the' two holes in guide-plate 39 to receive bolts 40 stop 28, whereupon the drill-tool 14 continues-to lower into the well-hole 12 ready to resume drilling.

'Now let us turn to Figure 3, whichshowsstill another variant of this invention.

In Figure 3, the toolaguide 24 has its -upper=endopen and unrestricted so that drill-tool 14 may extend up through the top of the tool-guide. Thus, when the drilltool 14 is'hoisted it will thread through the tool-guide 24 until the lower portion of the drill-tool 14 (which is the bit 33 and is of a larger diameter than the bottom opening of tool-guide 24), engages with the lower portion of the tool-guide and carries .it along with the tools as they are hoisted further. From this point .the tool-guide and drill-tool reacts in the same manner as previously described for Figure 2.

In lowering the toohguide, the drill tool is'lowered, as previously described for Figure 2, and the drill-tool and tool-guide 24 drop back into alignment with the well-hole 12 under theinfluence of their own weight. The rate of descent of the tool and its guide is controlled by the winch-brake as the winch pays out line and lowers the drill-tool.

In Figures 4, 5 and 6, a second form of constraining means is shown, namely: a slotted constraining means, which has been substituted for the lever arms 25 as shown and described in Figures 1, 2, and 3. The same referencenumbers are used in describing Figures 4, 5, and 6 as were used in describing Figure 1, wherever the parts are the same.

In describing this invention as shown by Figure 4, 11 is the frame of a cable-tool drill with a hole 34 in the frame for the drill-tool 14 to be lowerable into the well-hole 12. The mast 36 has its inside (nearest the well) face more nearly vertical, whereas the mast 17 in Figure l is inclined toward the well. This is desirable in that much of the bracing and cross-beams, as shown in Figure 1, may be eliminated without sacrificing rigidity. However, by using such a mast, it is no longer practical to move the tool-guide 24 and drill-tool 14 toward the mast, because the clearance between the mast and the tool-guide has been decreased by an amount so that the clearance is insufiicient to remove the tool-guide from the line of drilling. Therefore, in this variant, the tool-guide 24 is moved upward and to one side of the mast when the bailer is to be used. This is done by the following type constraining means:

Referring to Figures 5 and 6, mast-plates 37 and 37a are welded to the mast 36, so that it is rigidly secured thereto. The mast-plates 37 and 37a have slots 38 and 38a cut into them at inclined angles. The slots in the two mast-plates are cut at different angles, but slot 38 in niast-plate 37, or the uppermost mast-plate, willlbe inclined at a greater angle, measured from the horizontal, than slot 38a in mast-plate 37a, (the lowermost mastplate). In Figure 5, the slot 38 in the upper mastplate 37 is inclined at approximately 60 degrees to the horizontal and the slot 38a in the lower mast-plate 37a is inclined at approximately 45 degrees to the horizontal, but let it be understood that this invention is not to be limited to this combination of degrees of incline; only that the upper slot be at a steeper incline than the lower, or that they both be at the same incline.

The tool-guide 24, has two guide-plates 39 and 39a welded to its side, one near the top and the other near the bottom thereof. The upper guide-plate 39 has two holes bored through its face to receive two bolts 40 and 406:. The centers of these two holes are to lie along a line that is inclined to the horizontal to the same amount as slot 33 (in Figure 5, this incline is 60 degrees). The lower guide-plate 39a has two holes bored in its face to receive bolts 41'and'41a and the centers of these holes lie along a line that is inclined to the horizontal to the same amount as slot 38a (in Figure 5, this incline is 45 V A spacer 42 has two holes through it matchand 40a. Bolts 40 and 40a are inserted through these holes in spacer 42, then through slot 38 and through the corresponding holes in guide plate 39 and fastened by nuts. The spacer 42-fits between the mast36 and mastplate 37 (Figure 6). The lower slide assembly is assembled by spacer 42a, (which is identical to 42) having bolts 41 and 41a inserted through the holes, through slot 38a, through the corresponding holes in guide-plate 39a and fastened by nuts in the same manner as described for the upper slide assembly.

The tool-guide 24 has an eyelet 30 rigidly fastened thereto for connecting rope 29. The .rope 29 passes over sheave 31 mounted above the tool-guide 24 on the mast 36. From sheave 31 the rope 29 extends downward to a point where a book 32 is attached to the rope 29 by tying it through an eyelet on the end of the hook 32. The hook end of part 32 is fastenable to the bit 33 of drill-tool 14.

In Figure 4, drill-tool 14 is threaded through the toolguide 24 and rope 15 is connected to the upper end of drill-tool 14 by a conventional connecting means. As winch-drum 21 winds on rope 15, the drill-tool 14 is lifted from well-hole 12 until the drill-tool 14 is lifted into the tool-guide 24 to a position where hook 32 may be hooked onto drill-tool 14 at the bit33. After the hook 32 engages the drill-tool 14, the operator lowers the drilltool 14'under the control ofthe power-winch, so that as the drill-tool14 is lowered, the rope 29 is pulled downward and thus tool-guide 24 is lifted upward and to the right (Figure 5) constrained by, slots38 and38a of mastplates 37 and 37a. Thus, the weight of the drill-tool retracts the tool and the tool-guide from the line of drilling' automatically and with a minimum .of'operations on the part of the operator.

More particularly, the slide assemblies constrain the movement of the tool-guide .24 asfollows:

When the tool-guide 24 is in the normal drilling position, the lower bolt 40a bears against the bottom of slot 38 and bolt 41a bears against the bottom of slot 38a, to hold the tool-guide in the lowered position for drilling. As force is applied through rope 29 to lift the tool-guide, the bolts 40, 40a, .41 and 41a slide along their respective inclined slots 38 and 38a to carry the tool-guide sideways along the course of these inclined slots as it is lifted upwards. Due to the fact that the slope of the incline in slot 38 .is greater than the slope of the incline in slot 38a, the horizontal travel of the top of the tool-guide will be somewhat less than the horizontal travel of the bottom of the tool-guide.

This will result in the tool-guide assuming a slanted position, which may more appropriately be described as a cant etfect. The cant effect is desirable for three reasons: (1) Due to the fact that the lower bell of the toolguide is of a larger diameter than the upper diameter of the guide, it is desirable to retract the lower portion of the tool-guide further horizontally away from the well than the top portion. (2) The cant effect decreases the tendency of the main rope 15 to jump thesheave, due to the fact that the tool-guide slants towards the center-line of the sheave when the tool is in the retracted position. (3) The cant effect of the tool makes it tend to swing like a pendulum while it is in the retracted position. Thus, the tool and tool-guide are allowed to return more smoothly from the retracted position.

After bailing is completed and it is desired to realign the tool-guide 24 and drill-tool 14 with the hole 12 for drilling, the operator engages the clutch on the drillwinch and raises the drill-tool 14. In so doing, slack is created in rope 29 and the tool-guide lowers by its own weight along the inclined slots 38 and 38a until bolt 46:: and bolt 41a bear against the bottom of slots 38 and 380 respectively. This is the normal drilling position and the tool-guide and tools are again lined up with the wellhole 12. When the tool-guide 24 is restored to its low- T o summarize; It willbe seen that the the tool" away from a follows:

1 1 .In a cable-tool sheave journaled in an elevated position on the-:mast, a cable-tool, a winch; a hoist-ropepassing from thew'inch drilling toapo'sitiori adjacent'the mast." a V 1 1 V 2. A cable-tool drill according to'claim 1,,further 'char- 1 r cred pqsitiomthe hoolc 32 maybe removed from drill- 100114. ':The operator thendisengages the winch clutch The length" of rope 29 and hook 32'will determine the height above the drill-frame11 to which the arm-m1 14, must'be raised to engage hook 32 with 'drill-t'ooll4.

'5, and 6,:could equally variant of Figure 3. a h variants here in describedemploy three alternative means of using vertical motion of the drilling tool to raise the tool-guide,

"to' stopthoisting the drilltool,. and thetool'isg-lowered into the well-hole, 12 under the control of the winchbrakeh" and two alternative means for constraining; the thus- 5 caused upwardmotion of the tool-guide to move it'and being drilled.

retracted from alignment 'with'the line of ;drilling='and then returned automatically into alignment 'with the line of drilling may A'tubular tool-guide 'is movable" upward and away from the line of drilling, and the direction and amount of movement is controlledby a constraining means. Moving'thedrill-tool verticallyl to engage 'or' disengage with 'the tool-guide will actuate this movement" of the .11001 V and tool-guide away from the line of drilling. l Said-'movements of the tool-guide and drill-tools are achieved auto be generically described to operate as position above the hole which" is The means- Whereby the tool-guide is automatically 3; -A ble-moidin ei oiq ifi a a 1 1 5 A cable -tooldrilljaccording to claim 4; vstill,furthei' characterized byfthe tact thatTthejslotin the upper mast-f; plate has 'a greater horizontal incline" than th'efsldt'iin l; the lower mast plate ,z to. allow the lower, portion or the tool-guide tormovejto & :pOsition furthr;awayf from the lineof idrilling than the top portion of theitoohguide, and

7 l accordingto characterized by the tact that I the 'means mounting the tool-guide to the mast comprisesf at: least or ei leveii arm;

means fpr pivotallyconnecting saidarm at one ofitsends to the tool 'guide" and its so therr ends" to .the l:mast;ljand ','a

stop meansfcohnectedtothe mast, sothatwhen the tool guide isiin its normal, drilling rposition saidrstop means bears. against-the leverrarm to holdithe, tool-guide positio Li 4- 4re talee in analgesia V acterized by the factzthatthe means mounting 'theritoolg guide to the mast comprises multiple mast-Plates rigidly connected to the mast,isaid pl ates having slots ,therem ihat" q di 1 1 s P Qnt 2 91 a uidep ates'iria' idly, coi inectedjo the' "tool-guide jspaced; longitudinally along oneiside thereof; multiplebolts adaptedto ibefitted a through the slots in the 1 mast-plates land bolted to the guide-plates, so'th at when the't ool-guidei is'in'the drilling. j position the bolts bear, against the lower point intthe in? 7 clinedjslotgand the bolts are free to slide ingthe slots to allow, the' tool-guide to move upwar d and away'frohi; the line of drilling 's the tool-guide' is 1ifted under the weightl V e ntthe tool-guideand'toolatajposition ofir est; a

j 6.'A"cable-tool}drill according tojclaim 1', f ur,the'r char-w acterizediby the factlthat the; cable-tool comprises a drill bit having a; 1argejr, cross'-sectional area than. the cross-g sectional area of zthetoolg'uide'; means ,gfo'r connecting the bit to the-lowerfend tot, the ,tdollwhereby' thefvertical matically by' vertical motion of thedrill toollunderthe influence of the winch through the rope. Movement-of,

the tool-guide and tool to realign same with the 'well hole drilling 1 position from the retracted position controllable 1 V to be understood-thatrthis inventionis not'to'bellim'ited iherein deto the specific form ;or arrangement :of parts scribed and shown i Weclaim: 1 if r drill 1 which comprises, a .ma'st; -a

over the. sheave and operatively-connected to IhgtQOltO j -raise and lower thetool,;and' an, integral elongatiefdtooh guide movably connected to the tool, the combination; of means mounting the tool-guide to. thegmast for yertlcal is achieved automatically by the potential energy of said a parts, with their'rate of movement back tora 'normal upward movemjnt of thetool throughfthe to'obguideiunder the influencefofl the jwinchfthrough. the .fl'rope' will; engage.

the, bit with the lowei; end Iof .,thei tool-gu'de andimove. J the tool tandgthe'l tool-iguideaiofit of; th l ne: of drilling a to a position of 'iest; land Is'till 'further characterized the fact that thelnieans mounting the"" tool-guide;toithe mast ,comprisesf -multipleflinashplates rigidly' connected;

to the mast, said plates having slots thereihi thatiarefmnfl 'clinedto-the horizontal; multiple g'uide-platesrigidly con nected'to thetool-guide spaced lorigitudinally along one 7 side thereof; multifale'bolts :to be fitted, through thejslot' in the mast-plate andfboltedto' the guide-platesQs o that- 7 whenthe tooleguide'i'sflin the drilling p'ositi'on the bolts I bear against-the'ilowe'r p'oint'jin' the inclined slots audfthe bolts [are free to slide lin the slots to allow the, 'tool guidq to move'upward and away frjom the line of drilling.

and lateralbodiljmovement thereof relative to the mast; Y

' a V and interlock means' supported on the, r nast,; movable relative, thereto and having, a, portion ther eof connected to the tool-guide, said interlock means having another 'por: 7

tion thereof adapted to be jcolnnectedto the: tool, whereby the interlock means i's.. movable under the weight ofthe tool as it moves'downwardlyfto'1ift' the;tool-guide and thereby move said guide; and saidto'ol out ojfjthe line of V acterized by the factthat the interlock nieansIcompriSeS;

a rope connected at one end to the-'tobl guide, operatively l 7. A'cable-too1 driIl-according'to claim ,6, still furthera V V eh'aracterized by the'facttliat the slot in thezupper mastplatejis ofiafgreaten horizontal incline thanitheslot m V thelower mast plate,jso as' to allow thelower portlorrofi the tool-guideto move to'ap o sition further away hori 7 V zontally from the line of drilling than the, top portion g of theto'olguiderand give'the'jtool-guide and tool a cant V 1 7 effect at apositionrofres i References; theifile of p t i h I V 'y T n JsrATEs IPAIENTVSL' V m ifs ill I 

